Abstract: A multifunction apparatus for the direct heat treatment of a medium- to high-carbon steel rod in a lower quench line and the treatment of low carbon steel in an upper quench line. A hot-rolled rod is transported on a conveyor in the form of a sequence of non-concentric rings, the conveyor, being operative between a first position in contact with the lower quench line and a second position in the upper cooling line. In the lower quench line the rod is subjected to controlled cooling in a coolant so that the greater part of any austenite in the entire length of the rod is substantially uniformly transformed to a fine pearlite structure. A heat holding vessel is operated under conditions that transforms any residual defects into pearlite.

Abstract: A method and apparatus for the direct heat treatment of a medium- to high-carbon steel rod in which the formation of martensite is prevented, even if the starting billet contains segregation. A hot-rolled rod is transported on a conveyor in the form of a sequence of non-concentric rings. The rod is then subjected to controlled cooling in a coolant so that the greater part of any austenite in the entire length of the rod is substantially uniformly transformed to a fine pearlite structure. The sequence of non-concentric rings of the rod is next held at a temperature of 450.degree.-630.degree. C. for a period of 60-300 seconds, with the pitch between each ring being made smaller than at the inlet of the conveyor. Accordingly, a pearlite transformation is effected of any residual austenite.